Bootstrap toolkit question

  For one of my BT applications, I need to be able to toggle the black menubar at the top of the page. When you're reading, the menubar is a distraction. 99 percent of the people who come there will not need it, understand it, care about it, etc. So, rather than have the whole menu present, I want to shrink it to a 16-by-16 icon (or less). Click the icon to make the menu visible. Click it again to hide it.
  Here's a screen shot to illustrate.
  I thought this would be simple, given my experience with the outline node type, but I've hit a problem. The image doesn't show up. It appears to be "behind" the black menu bar. I poked around and thought that it was the result of it having a z-index of 5. So I gave my image a z-index of 6. Still doesn't show. Gave it a z-index of 60. Still no show.
  This is the advantage of using a common toolkit, I hope. It doesn't matter what the graphic is, as long as I can get it to display. Any ideas?